Genetics Flashcards by Amy McGovern

What is the name of the small self-replicating DNA molecule found in bacteria that can be used as a cloning vector

Plasmid

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DNA agarose gel electrophoresis

DNA migrates from the negative to the positive electrode
Ultraviolet (UV) light is used to visualise the DNA bands in the gel
Ethidium bromide binds to the double stranded DNA
Smaller DNA molecules migrate faster than larger DNA molecules

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What enzyme is used to seal the DNA sugar phosphate backbone between the cloning vector DNA and the DNA insert during molecular cloning

DNA ligase

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What is the theoretical number of polymer chain reaction (PCR) amplicons expected after forty cycles with a starting number of 1 target sequence

c) 1 X 2^40 = 1,099,511,627,776

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5) During a typical polymerase chain reaction (PCR) cycle DNA samples are first heated to 94oC and then cooled to 55oC and then heated again to 72oC. What are each of the different temperature steps

c) 94oC = DNA denaturation step 55oC = primer annealing step 72oC = enzyme extension step

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Components of a typical PCR reaction

Taq DNA polymerase enzyme
dATP,dCTP, dGTP, and dTTP nucleotides
Synthetic single stranded oligonucleotide DNA primers

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The method of sequencing DNA using dideoxynucleotide triphosphates (ddNTPs) is called what

The Sanger DNA sequencing method

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What is the correct name for the widely used gene that allows bacterial colonies carrying a DNA insert to be selected during the molecular cloning process based on their ability to metabolise the sugar X gal

LacZ

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What is the target region of a genome that is amplified during the polymerase chain reaction (PCR)

Amplicon

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Nitrogenous bases found in biological DNA

Adenine, Guanine, Cytosine and Thymine

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What is the function of the enzyme DNA polymerases

Catalyses the synthesis of a new DNA molecule using a template DNA strand

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What is the full term for the acronym mRNA

Messenger ribonucleic acid

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The biochemical process of translation is carried out by which molecule

The ribosome

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Examine the coding DNA sequence of a gene below (note only one of the strands is shown). A mutation has been discovered in this gene which changes a guanine nucleotide (G) to a adenine nucleotide (A) (Note the mutation is highlighted in underline and bold). The coding sequence of the normal gene and the mutated sequence of the gene are shown
Normal DNA sequence: TAC GGG CCC GTG
Normal mRNA sequence: AUG CCC GGG CAC
Normal polypeptide sequence: Met Pro Gly His
Mutant DNA sequence: TAC GG CCC GTA
Mutant mRNA sequence: AUG CCC GGG CAU
Mutant polypeptide sequence: Met Pro Gly His

Silent mutation

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When snapdragon plants that produce red flowers are crossed with snapdragon plants that produce white flowers the resulting offspring produce pink flowers. What Is the genetic term used to describe this phenomenon

Incomplete dominance

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Who is considered to be the father of genetics

Gregor Mendel

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What is the meaning of the genetic term epistasis

One gene alters the expression of another gene

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What is the correct description for a diploid organism with a pair of identical alleles for a character

Homozygous

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Do prokaryotic cells produce a nuclear membrane?

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How many rounds of cell division take place in eukaryotic meiotic cell division

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The chromatin in eukaryotic cell nuclei consists of ——-

DNA and Protein

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If mottled overo stallions are matted with mottled overo mares what would the phenotypic proportions of foals born

50% mottled overo foals 25% solid coloured foals 25% pure white still born foals

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A scientist crosses two true breeding varieties of pea plant. The first variety consists of plants that always produce yellow and round seeds. The second variety consists of plants that always produce green and wrinkled seeds. The F1 hybrid mating consists of plants that produce yellow and round seeds. What is the expected ratio of phenotypes in the F2 generation that is produced from mating the F1 plants with each other

9 Yellow Round 3 Yellow Wrinkled 3 Green Round 1 Green Wrinkled

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What does r RNA stand for

Ribosomal RNA

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What is the definition of the term cell cycle

The series of events in a eukaryotic cell from one cell division to the next

The ovine haploid chromosome number is 27. Ignoring recombination how many chromosomal combinations can result during meitotic cell division in sheep

2^27 = 134,217,728

What is the term used to describe the genotype of an X linked gene in male mammals

Hemizygous

What is the definition of the term pleiotrophy

The genetic effect of a single gene on multiple phenotypic traits

What process can enhance the evolutionary adaptation of a species to its environment

Natural or artifical selection

The frequency of cystic fibrosis (a recessive genetic disorder) in Ireland is approximately 1 in 1600. Therefore assuming Hardy-Weinberg Equilibrium which of the answers below represents the best estimate of the frequency of the mutant cystic fibrosis allele in the Irish population

0.025

Who first developed the concept of the genetic linkage map

Thomas Hunt Morgan and Alfred Sturtevant

A colour blind woman has children with a man who has normal vision. What are the expected offspring proportions from this mating

50% carrier females 50% colour blind males

S Wright, J.B.S Haldane and R.A fisher initiated which branch of genetics

Population genetics

In a region of west Africa with a high incidence of malaria, the frequency of sickle cell anaemia (a recessive genetic disorder) in the human population is 1 in 30. Therefore assuming Hardy Weinberg Equation (HWE) which of the answers below represents the best estimate of the mutant sickle cell anaemia in this population

0.18

Scientific evidence suggests that the cheetah (Acinoyx Jubatus) has undergone how many population constrictions that led to reductions in genetic variation

An evolutionary founder event will act to

Increase genetic drift

What is the definition of the term genetic linkage

The relationship between two genes that are physically close on the same chromosome and tend to be transmitted from parents to offspring as a single unit

What are removed from transcribed protein coding RNA during mRNA processing in eukaryotes

Introns

What can cause mutation in the sequence or structure of DNA molecules

Exposure to chemical mutagen Exposure to X Ray radiation Exposure to Ultra Violet (UV) radiation

The biochemical process of transcription is carried out by which molecule

RNA polymerase

The ribosome is composed of

Protein and RNA

Who discovered the three dimensional structure of DNA

James Watson and Francis Crick

Terms relating to the structure of DNA

Hydrogen bond Purine Pyrimidine

What is the function of the retroviral enzyme reverse transcriptase

Transcribes a DNA molecule from a single stranded viral RNA template

What is the Sanger laboratory method used for

Determining the sequence of bases in a DNA molecule

What is the theoretical number of polymerase chain reaction (PCR) amplicons expected after 40 cycles with a starting number of 10 sequences

10 X 2^40= 10, 995, 116, 277, 760

Which is the name for a widely used gene that confers resistance to an antibiotic during bacterial cloning of recombinant DNA

amp^R

Methods used to produce transgenic animals

Microinjection of foreign DNA into embryo pro nuclei Replacement of an oocyte nucleus with the nucleus of a transgenic donor cell Use of modified retroviruses as vectors to carry genes into an embryo

What bacterial species can be used to produce transgenic plants using recombinant TI plasmids

Agrobacterium tumefaciens

What does the Ti stand for in Ti plasmid

Tumour inducing

Transgenic golden rice was developed to alleviate deficiency of what vitamin in certain human populations

Vit A

Processes that occur in the eukaryotic cells nucleus

DNA replication, RNA processing, Transcription

With respect to population genetics, a gene pool consists of

The total of all alleles across all genetic loci in a population

What was the mechanism of the evolution of species proposed by Charles Darwin in the Origin of Species published in 1859

Natural Selection

Characteristics of a codon

Its consists of three nucleotides It never codes for one or more amino acids It’s the basic unit of genetic code

Cellular components involved in translation

Mature mRNA tRNA Ribosomes

The anticodon of a particular tRNA molecule is

Complementary to the corresponding mRNA molecule

What is the size of the haploid human genome in base pairs

3.2 Giga base pairs (Gbp)

The combined human genome consists of the nuclear genome and the ....

Mitochondrial genome

What is meant by the term genetic drift

The random fluctuations in a populations genetic structure due to chance over time

Examine the following mature m RNA sequence 5’ AUG-AAA-GCG-UUU-UGA-3’. Using genetic code what is the correct sequence of amino acids specified by this frame

MET – LYS – ALA- SER – PHE – STOP

Genetic studies have revealed a death of genetic variation in the Northern Elephant Seal populations. What is the major contributing factor that has resulted in this lack of variation

A major population bottleneck effect in the 19th Century

What force of microevolution permits populations to become better adapted to their environment

Natural Selection

What are the correct temperatures at each stage of a typical PCR reaction

Temp A = 55oC Temp B= 72oC Temp C =94oC

Flower colour in peas is controlled by a single gene for which there are two alleles P=Purple and p=white. Purple flower colour is dominant to white. The plant is homozygous for purple and for white flowers. What are the expected genotype frequencies of the offspring

All offspring will have a Pp genotype

A point mutation which causes the reading frame of m RNA molecule to be altered is called

Frameshift mutation

Physical and chemical agents that are mutagens

UV light X Ray Atomic Radiation

What enzyme is responsible for synthesising m RNA under the direction of the genes DNA sequence

RNA polymerase

How many stop codons are there in the genetic code

Conditions of the Hardy Weinberg Theorem (HWE)

The population must be very large No natural selection occurs in the population Random mating is occurring in the population

The biochemical process of transcription is carried out by which molecule

RNA polymerase

How many start and stop codons are there in the genetic code

What is the name given to a model of DNA replication whereby the two DNA strand parental molecule separate and each single strand then functions as a template for the new complementary strand

Semi conservative replication

What molecule is responsible for transferring the correct amino acid at the size of translation

Transfer RNA

Under the assumption of the Hardy Weinberg Equation (HWE) what would be the expected genotypic frequencies for a gene with two alleles (A and a) where the frequency of A allele p is 0.60 and the frequency of the a allele q is 0.40

AA = 0.36 aa = 0.16 Aa = 0.48

The bovine haploid number is 30. Ignoring recombination how many chromosomal combinations can result during meitotic cell division in cattle

2^30 = 1,073,741,824

What codon sequence represents the eukaryotic START codon

AUG

What does DNA stand for

Deoxyribonucleic acid

James Watson and Francis Crick along with Maurice Wilkins won the Nobel Prize in 1962 for what scientific breakthrough reported in 1953

The elucidation of the 3 dimensional structure of DNA

Description of metaphase in mitosis

The cells chromosomes align along a central plain in the dividing cell

During the cell cycle when is the cells genetic material (i.e. the genome) replicated

S phase

Colour blindness in humans is an X linked recessive disorder. A female who is colour blind marries a colour blind man. If the couple have children what will the phenotypes of the offspring be

All children will be colour blind

When short horn cattle with red coat colour are bred with short horn cattle with white coat the resulting progeny all display roan coat colour in which red hairs are intermingled with white hairs. This genetic phenomenon is an example of

Co-dominance

What is mitosis

A form of cell division in which a diploid parent gives rise to two genetically identical daughter cells

Functions of mitosis

Cell repair Organism growth Organism development

Composition of chromatin

A complex of DNA and protein

What is the name of the pentose sugar found in DNA

Deoxyribose

What is the name of the organelle that facilitates the translation of messenger RNA into a polypeptide

Ribosome

What is meiosis

A form of cell division in which a diploid parent cell gives rise to four genetically different haploid gametes

Haploid number of human chromosome

n = 23

Factors that contribute to the genetic variation that arises between generations

Independent assortment of chromosomes during meiosis The crossing over of non -sister chromatids during meiosis Random fertilisation of gametes

What molecule is responsible for transferring the correct amino acid at the site of a codon during translation

tRNA

Who wrote the book on the origin of the species

Charles Darwin

The frequency of a recessive genetic disease causing allele q in a population is estimated at 0.2. The population is comprised of 1000 individuals. Assuming Hardy Weinberg Equation how many individuals are predicted to be affected by the disorder.

Positive natural selection will act to...

Increase the frequency of a favourite allele in a population

What’s the most extreme form of inbreeding

Self-fertilisation

Microevolution definition

The change in allele and/or genotype frequencies of a population from one generation to the next

What’s the phenomenon called where some transfer RNA anticodons recognise two or more different codons

Wobble

Sequence of events during the process of gene expression

DNA – RNA – polypeptide – protein

What insect is considered to be the workhorse of genetics

The fruit fly (Drosophilia Monogaster)

Who first developed the concept of the genetic map

Thomas Hunt Morgan and Alfred Sturtevant

What percentage of transgenic offspring would be expected using transgenesis by transfer of transfected nuclei?

1-5%

A coenocyte is…

A multinucleated cell generated from multiple nuclear divisions without cytokinesis

What is the theoretical number of polymerase chain reaction (PCR) amplicons expected after 35 cycles with a starting number of 20 target sequences?

20 x 2^35 = 687,194,767,360

The dwarf phenotype in Dexter cattle is associated with a lethal recessive allele. The lethal recessive condition is termed ‘bulldog’, which gives rise to stillborn calves with severe facial deformities. Male dwarf Dexter cattle are crossed with female dwarf Dexter cattle. What would be the expected phenotypic proportions of the offspring produced?

50% dwarf calves | 25% normal-sized calves | 25% stillborn ‘bulldog’ calves

ABO blood group system in humans is controlled by...

Controlled by a single gene with two codominant alleles and one recessive allele

What term relates to the structure of double-stranded DNA?

Hydrogen bond

Alan and Betty are both carriers (heterozygotes) for a recessive genetic disorder. If Alan and Betty have two children, what is the probability that only one of the two children will be affected by this genetic disorder?

0.2500

Sickle cell anaemia (a recessive genetic disorder) affects approximately 1 in 130 people in Cameroon, a country in West Africa. Therefore, assuming HardyWeinberg Equilibrium (HWE), which of the answers below represents the best estimate of the frequency of the mutant sickle cell allele in the Cameroonian population?

0.088

The genetic distance between two genes is 7 centimorgans (cM). What is the expected recombination frequency between these two genes?

0.07

Who showed that the material in dead bacterial cells that can genetically transform living bacterial cells is actually DNA?

Oswald Avery, Colin MacLeod, and Maclyn McCarthy

A colour-blind man has children with a woman who is a carrier for this genetic trait. What are the expected offspring proportions from this mating?

50% carrier females | 25% colour-blind males | 25% normal males

The incidence of cystic fibrosis (a recessive genetic disorder) in Germany is approximately 1 in 3,300. Therefore, assuming Hardy-Weinberg Equilibrium (HWE), which of the answers below represents the best estimate of the frequency of the mutant cystic fibrosis allele in the German population?

0.0174

The term endosymbiosis refers to what biological phenomena?

A scientific theory for the origin of eukaryotic mitochondria and chloroplasts

The term ‘semi-conservative’ is used to refer to the mechanism governing which of the following molecular biological processes?

Replication of DNA

Under the assumption of Hardy-Weinberg equilibrium (HWE), what would be the expected genotype frequencies for a gene with two alleles ('A' and 'a') where the frequency of the 'A' allele (p) is 0.70 and the frequency of the 'a' allele (q) is 0.30?

AA = 0.49 aa = 0.09 Aa = 0.42